Proposed is the development of a blood test strip for cholesterol. Plasma is separated on the strip from cells by a patented filtration process through a glass fiber fleece, collecting the plasma on a detachable recipient member, and eluting it into a liquid reagent. Cholesterol esterase (CHE) and oxidase (CHOD) are incorporated in dry form on the strip. Quantitation is based on a "threshold" assay for peroxide, generated by CGE and CHOD. The assay comprises a "scavenger" and a "signal" reaction. The below threshold amount of peroxide, equivalent to the 200 mg/dL cholesterol cutoff recently suggested by the NHLBI, is reacted in the scavenger, the above threshold amount in the signal reaction. Thus, by elimination of large color backgrounds, and choosing highly sensitive signal reactions, visual interpretation is greatly enhanced. The device does not require an instrument making it economical and fast for mass screenings and self-monitoring. Feasibility of the test principle has been demonstrated for peroxide and cholesterol from serum. The proposed work comprises final selection of optimal plasma separation and recipient member materials, optimization of the reagent system, and the manufacture of functional prototype test strips capable of differentiating concentration intervals of between 10 and 20 mg/dL around the 200 mg/dL cutoff level.